Mike;
I think you are correct. 43 year old parts have a way of losing their edge!
My water pump is in good condition but not as efficient as the later type. The original rad, according to my rad shop, is in great shape and not plugged, but as we now know, is not up to the performance of newer designs. My car also came with a 13" Flex-O-Lite Flex fan, ( hold the rocks – I didn’t put it on there!) which I am replacing with a 14" rigid fan, and a recommended 11" thermo pusher.
For all I know the head gaskets were installed upside down or front to back by the engine builder, but before I go to the trouble and expense of hauling the engine out of the hole to check, I’m going to do everything else that’s easier and hope the HG’s are in correctly.
BTW, my engine is a 1967 "thick-wall" block, bored to 80 thou and stroked to the max, and measures 331 cu.in. It has all new internals built to produce approx 330 hp at the crank. It works fine in all respects except for the cooling. If I can get it under control, it will be a fine cat indeed.
Thanks for yor input Mike.
Cheers,
Dave